/**
 * Copyright (c) 2013 Craig Condon
 * Copyright (c) 2015-2016 Jared Allard
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 **/

'use strict';

let path = require("path"),
  fs = require("fs");

/**
 * Accessort for embed
 **/
const accessor = function(key) {
  if (embeddedFiles.hasOwnProperty(key)) {
    return new Buffer(embeddedFiles[key], 'base64');
  } else {
    //file was not embedded, throw err.
    throw new Error('Embedded file not found');
  }
}

/**
 * Embed files.
 *
 * @param {array} resourceFiles - array of files to embed.
 * @param {string} resourceRoot - root of resources.
 * @param {function} compelte   - callback
 **/
function embed(resourceFiles, resourceRoot, options, complete) {
  const encode = function(filePath) {
    return fs.readFileSync(filePath).toString('base64');
  }

  resourceFiles = resourceFiles || [];
  resourceRoot = resourceRoot || "";

  if (!Array.isArray(resourceFiles)) {
    throw new Error("Bad Argument: resourceFiles is not an array");
  }

  let buffer = "var embeddedFiles = {\n";
  for (let i = 0; i < resourceFiles.length; ++i) {
    buffer += JSON.stringify(path.relative(resourceRoot, resourceFiles[i])) + ': "';
    buffer += encode(resourceFiles[i]) + '",\n';
  }

  buffer += "\n};\n\nmodule.exports.keys = function () { return Object.keys(embeddedFiles); }\n\nmodule.exports.get = ";
  buffer += accessor.toString();
  complete(null, buffer);
}

module.exports = embed;